Gun sight



July 16, 1940. E, g, GREGORY v 2,207,857

GUN SIGHT l'illd Ja 2:5. 1939 2 Sheet-Sheet 1 li lVENTOR m c. *4 BY ATTORNEYS E, E- GREGORY GUN SIGHT Filed Jg-n. 23, 1939 July 16, 1940.

2 Sheets-Sheet 2 Hllllll INVENTOR BY Q w il [Dams mug QM-A5 ATTORNEYS f Fig. 3 ma schematic diagram Patented July 16.1940 a um'rsn STATES PATENT orncs v 2 v I c3351! I v as a. drum. Stirling. N. J. Applloiflfll Ill!!!" 23, 1939, Serial No. 25!.9 noun. (or. ss-m This invention relates to gun sights, and in particular to certain new and useful improvements in a field-shooter's binocular gun sight.

Theobiect of this invention is to increase the v speed and accuracy with which a gun used in the field may be brought into a desired alignment, while permitting the shooter to use both eyes to find, follow, and gauge the distance to his target.

Prior sighting aids, for shotguns in particular.

a have been devised either after the pattern of rifle sights or on the principle of a narrow sighting rib. Neither of these methods is adapted to binocular use. The most common adaptation of the rifle sight to shotgun use is the ivory bead mounted .singly' or paired. when the shooter attempts to focus his two eyes on the target. and at the same time to align his weapon by means of such beads the phenomena of human binocular vision impose insuperable difilculties. He necessarily sees double all objects not in the plane on which his eyes are focused. The operation of the same phenomena transforms the narrow sighting rib, so effective when squinted over by one eye, into a pair of blurred lines. The purpose of this invenv tion is to transform the. handicap heretofore imposed by these phenomena upon binocular shooting into a positive advantage. The way in which I accomplish this result will become clear by reference to' the accompanying drawings and from 30, the following description:

' Fig. 1 is a perspective drawing of a doublebarreled shotgun equipped with my invention;

Fig. 2 is a cross-section of said double-barreled shotgun through the line 2-2 of Fig. 1;. showing the operation of my invention;

Fig. 4 is an elevation of my invention enibodied as a detachable sight adapted'for attachment to.

an existing double-barreled shotgun; Fig. 5 is a cross-section of the form of my I invention shown in Fig. 4 through the line 5-! of Fig. 4 and indicating the barrels of a doublebarreled shotgun;

Fig. 6 is a plan view of a modified construction 45 of my invention;

Fig.7isaplanview ofamodifiedconstruction v of my invention:

Fig. 81s aplanviewofamachinegunequipped with a modified construction of my inventio 5o Fig. 9 is a cross-section through Fig. 8 on the line 2-0;

Fig. 10 is a plan view of a machine gun equipped with a range-finding modification of my invention;

Fig. 11 is a cross-section through Fig. 10 on the line I l-i I;

Fig. 12is a cross-section through Fig. 10 on the linen-i2;

Fig. 13- shows a modified range-finding form of I) my invention: and

Fig. 14 is a longitudinal section through Fig. 13 on the line l2l2. I

In Figs.'1 and 2 is shown a shotgun I having a rectangular sighting surface 2, substantially plane, integrally aiilxed to the barrels]. Said t surface 2 is substantially equal in length to said barrels 3, and is slightly greater in width than the average interpupilary distance of the human eyes. Its surface is preferably finished by some method whereby light reflection is reduced to a minimum. 1o

Fig. 3, a schematic diagram, shows the eyes 4 of a shooter looking along the sighting surface 2 through the converging lines of vision 5 at a target I. The actual rectangular sighting surface 2 is shownin solid lines in perspective and is 15 slightly wider than the interpupilary distance of said eyes 4. The lines of vision 5 are shown as arrows. The two planes diagonally designated as A1-.-B1 and Ar -Br, equal to said sighting plane 2 and indicated by dashed lines, represent the 0 images of said sighting plane 2 visible to the right and left eyes of the shooter respectively, when his two eyes 4 are focused on the target 6, and show the apparentrespective positions of these images.

The narrow plane diagonally designated Ar-Bi, up .and indicated by. the hatched area, represents a narrow opaque sighting line in the center of the plane 2 which is visible to the shooter when his eyes 4 are focused on the target 0. This narrow plane AP-B: is formed by the overlapping of the images seen by each eye separately, and is the 1 only part of the actual sighting surface 2 appearing opaque to the shooter when his two eyes 6 are focused on the target 6, the balance of the images Ai-Bi and ArBr seen by the right and left eyes respectively then appearing transparent. The width of this apparent narrow plane Ar-Ba is just one-half the total amount by which the actual sighting plane 2 is wider than the interpupilary distance of the eyes 4. 40

The phenomena of binocular vision thus produce for the-shooter a distinct narrow sighting line Ar-Bl equal in length to sighting surface 2, and do so without conscious effort or eyestrain on the part of the shooter. the effect of the ivory bead system of sighting, no distracting shift .cf focus from sight to target is necessary, and, in contradistinctiqn to the effect of the narrow rib system, the visible effective sighting line is long and clear. .The manifest advantage of along sighting radius over a short one in reducing the effect of visual error is well recognized in the sighting art. I

- The foregoing explanation of the operation of my invention shows that it isnot necessary that 55 the sighting surface 2 be geometrically plane. On the contrary the controlling limitation on the geometry of this surface is that it be slightly wider than the interpupilary distance of the used, and

the use of a substantially plane surface is preferg m contradistinction to able merely as providing no distracting light reflections.

Figs. 4 and 5 show the sighting piane'2 embodied in a detachable unit with clips I adapted to attach it to particular existing weapons, for example, to the barrels I of a double-barreled shotgun.

Figs. 6 and I show a modified construction of my invention in which the sighting'surface is slightly trapezoidal, not rectangular, in shape. In Fig. 6, the trapezoidal sighting surface I has its greater base I at the end nearer the eyes I of the user. The width of said greater base I may be made slightly wider than the greatest normal interpupilary distance of human eyes, and the width of the smaller base II may be made slightly wider than the smallest normal interpupilary distance of human'eyes. In Fig. 7, the trapezoidal sighting surface I! has its smaller base II at the end nearer the eyes 4 of the user. The width of said smaller base II may be made slightly wider than the smallest normal interpupilary distance of human eyes, and the width of the greater base I may be made slightly wider than the greatest normal interpupilary distance of human eyes. The difference in width between the width of the smaller base I and the wider base II thus constructed is on the order of -15 millimeters, this being the difference between the smallest and greatest normal interpupilary distance of human eyes. Thus, the taper resulting from the employment of this trapezoidal sighting surface is small and the sides thereof remain substantially parallel.

The effect of thus slightly tapering the sighting surface is to make a single surface adaptable to all normal people. When tapered as in Fig. 6, the-apparent narrow sighting line II formed by the phenomena of binocular vision will appear tapered with its narrow end away from the user. When tapered as in Fig. 7, the apparent sighting line II will appear tapered with its wide end away from the user. The length of these apparent sighting lines will equal in. each individual case that part of the length of the tapered sighting surface which is wider than the user's interpupilary distance. In those cases in which this length is less than the whole length vof the tapered sighting surface, when said surface is tapered as in Fig. 6, the apparent sighting line will appear to begin at the end of the surface near the user, when tapered as in Fig. 'I, at the end-away from the user. Thus the advantage of tapering as in Fig. 8 is to obtain an apparent sighting line II tapering toward the target; the advantage of tapering as in Fig. '1 is to obtain an apparent sighting line II giving a longer effective sighting radius.

vThe slightly trapezoidal sighting surface I, shown in Fig. 6, may also be made so that its greater base I is slightly wider than the greatest effective interpupilary distance of the individual user, that is the interpupilary distance of an individual when his eyes are focused on a very distant obiectand its smaller base II substantially'equals or is slightly less than the smallest elective interpupilary distance of the individual user, that is the interpupilary distance of the same individual when his eyes are focused on a near object, say 20 feet away. The difference between the width of the smaller base land the the greater base II thus constructed is small.

and the sides of the sighting surface remain substantially parallel. I

The eifectofthusslightlytaperingthesighting surface isto make the length of the apparent narrow sighting line II vary in length with slightly changing interpupilary distance of the individual shooter. Since this interpupilary distance will vary with the distance to the target on which the shooter's eyes are focused, and since the sighting line II is only apparent when the surface I is wider than the effective interpupilary distance of the shooter, the length of the sighting line H becomes shorter as the distance to the target becomes greater. This results in automatic elevation of the muzzle in order to keep the apex of thesighting line II on the target, and is a great aid in overcoming the trajectory drop of shotgun pellets.

The modified forms of construction of my invention shown in Figs. 8-12 are particularly adapted-to use on water-jacketed machine guns, but may be applied to any object to be aimed. The sighting surface II shown in Figs. 8-9 is the outer cylindrical surface of a water Jacket,

encasing the barrel II of the machine gun II. This surface is so constructed that its effective width D is slightly greater than the interpupilary distance of the human eyes. It then operates when the eyes of the user are focused on the target to form an opaque narrow sighting line as shown in the schematic diagram, Fig. 3.

The sighting surface II shown in Figs. 10-12 is the outer slightly conical surface of a water- 'Jaclret' encasing the barrel II of the machine gun II. This surface is so constructed that its effective width at the far end air is substantially equal to or slightly less than the smallest effective interpupilary distance of the individual user and its effective width at the near end d: is slightly wider than the greatest effective interpupilary distance of the individual user. It then operates to form a narrow opaque tapered sighting line whose apparent length varies with range of the target on which the eyes of the user are focused in 'the manner hereinbefore described.

The modified range-finding construction of my invention shown in Figs. 13-14 is essentially a combination of an opaque line forming sight II, of the type hereinbefore generally disclosed, and an optical cross forming sight II, of the type disclosed in my Letters Patent No. 1,350,153.

The optical cross" forming sight II, placed at far end ofslght II, is a tapered shape, the base of which is slightly wider than the interpupilary distance of the human eyes. When the user of this range-finding modification of my invention looks along the "opaque line" forming sight II and focuses his eyes on the target, he sees two images of the sight 20. These images appear transparent and in overlapping form an opaque central tapered imase. the apex of which determines the point which should be aligned with the "opaque line" formed, by the sight II and rested on the target. The farther away the target, the lower appears this apex, thus giving automatically corrected muzzle elevation for varying rinses.

The effective shape of the taper of'sight II is operatively determined in the vertical plane, and is varied to accommodate the ballistic characteristics of the particular weapon with which it is employed. The angle a at which sight II meets sight II is determined by the effect of sight II on the opaque line forming characthe taper of sight must be relatively less than 1 when employed separately as an optical cross" forming sight, in orderto obtain an equally effective taper in the vertical plane.

The operation of this combination produces achieved with an opaque line forming sight positive alignment than can be achieved with an optical cross forming sight alone.

The operator of a machine gun employing my invention is naturally in the optimum position effectively to use' the sight. The proper manner is for the shooter to place his eyes directly behind and slightlyabove-the sighting surface. A slight offset ofthe stockmay be founduseful in comfortably attaining-the correct position, but conventional guns maybe usedas well with .a little practice. I I i While I have :described my invention particureled construction guns, it may 'be used in connection with any instrument to be aimed requiring quick and accurate alignment while the user thereof concentrates his visual effort on the point'to be aligned with. In parparticular structure disclosed, therefore, must be taken as an illustration and not as a limitation of my invention.

I claim:

relation to said instrument having substantially straight apparent longitudinal boundary edges, a width slightly greater than the interpupilary tially straight apparent. longitudinal boundary edges, a width slightly greater than the interpupilary distance of the human eyes and a length sufiicient to be efiective'as a sight for said in-.

strument.

aimed, an elongated sighting surface in fixed rea width at the rear end slightly greater than the eyes, a width at the irontendslightly greater than the smallest normal interpupilary distance of human eyes and a length sufiicient to be effective as a sight for said instrument.

5. As a binocular sight for an instrument to beaimed, an elongated sighting surface in fixed straight apparent longitudinal boimdary edges, 'awidthattherearendslightlygreaterthan human eyes, 'a width at the front end slightly a greater range-finding effect than can be alone, and at the same time produces a moreof using a shotgun equipped .with my invention larly in connection with shotgunsoi doubIe barf tlcular, my invention is readily adaptable'to rifles, pistols, blowguns, and shotguns of all types. The

1. As a binocular sight for an instrument to be aimed, .an elongated sighting surface in fixed distance of thehuman eyes and a length suflifixed relation to said instrument having subs'tan- 4. As a binocular sight for aninstrument to be lation to said instrument having substantially straight apparent longitudinal boundary edges;

greatest normal interpupilary distance of human I optical eilect.

relation to said instrument .having substantially the smallest normal interpupilary distance of greater than the greatest normal interpupilary distance of human eyes and a length suflicient to bev efiective as a sight for said instrument.

6. As a binocular sight for an instrument to be aimed, an elongated sighting surface in fixed relation to said instrument having substantially straight apparent longitudinal boundary edges and a width at the rear end slightly greater than the greatest effective 'interpupilary distance of the individual user, a width at'the front end substantially equal to the smallest effective interpupiiary distance of the individual user and a length sufiicient to be effective as a sight for said instrument.

'7. As a binocular sight for an instrument to be aimed, an elongated substantially cylindrical sightingsurface in fixed relation to said instruhuman eyes and a length sufiicient tobe effective as a sightfor saldinstrument.

8. As a binocular sight for an instrument to be aimed, an elongated slightly frusto-conical sighting surface in fixed relation to said instrument having substantially straight apparent longitudinal boundary edges, a diameter at the rear end slightly greater than the greatest normal interpupilary distance of human eyes, a diameter at the front end slightly greater than the smallest normal interpupilary distance of human eyes and a length sufiicient to be effective as a sight for said instrument.

9. As a binocular sight for an instrument to be aimed, an elongated slightly frusto-conical sighting surface in fixed relation to saidinstrument having substantially straight apparent longitudinal boundary edges, a diameter at the rearend slightly greater than the greatest effective interpupilary distance of the individual user, a diameter at the front end substantially equal to the smallest efi'ective interpupilary distance of the individual user and a length sumcient to be efprising a tapered member the base of which coincides with the front end of said elongated surface and the upper surface of which meets said elongated surface at an obtuse angle, the shape of the taper of said member determined by the shape of the taper of its projection parallel to theaxis of said elongated surface according to the ballistic characteristics of the weapon on which it is employed which produces proper. automatic elevation of that weapon by binocular ii. In combination with a shot gun as a sight therefor and aiiixed horizontally on the upper surface of,parallel to, and coincident in length with the barrel or barrels thereof, a plane sighting surface having straight longitudinal boundary edges and a widthslightly greater than the inter-pupilary of human eyw.

4 ELI EGREGORY. 

